The RESILIO project addressed pluvial flooding by reducing the speed of water runoff through the installation of blue-green roofs on a range of building types but predominantly in social housing. The ‘blue’ refers to the runoff effect whereby water is stored on the roof during heavy rainfall and released before the next heavy rainstorm is forecast. The ‘green’ refers to the vegetation growing in a substrate above the water storage and which contributes to biodiversity in the city. Blue-green roofs are just two of the functions of multi-functional roofs, which also include solar energy and, sometimes, can provide safe social spaces at an affordable cost. The project’s target to create 10 000m2 (the size of two football pitches) of blue-green roofs was exceeded by 2500m2. The project also reduced the runoff in times of heavy rain in key locations, created a localised cooling effect in upper floors, and benefitted biodiversity.
RESILIO included a programme of engagement with local communities to explain the project on the ground by visiting local shopping centres and other community facilities and schools. The project used a cargo bike with a mini version of a blue-green roof as a teaching aid in local streets to illustrate the layers of the roof: (crate tanks, substrate and vegetation).